A man suffered a 10in slash wound to his neck during a fight in Spalding.
Police say four men were involved. It happened at about 10.50pm on Saturday (June 20) at the junction of Vine Street and Abbey Passage (behind Hills Furniture Store).
Det Insp Dave Rimmer said: “Thankfully the wound was relatively shallow and the male was later released from hospital following treatment., but I am very concerned about what could have happened in this incident.
“I would urge anyone who may have seen this incident, or has any information about it, to come forward.”
Anyone with information is asked to contact Spalding CID by dialling 101 and quoting incident 523 of June 20. Report crimes anonymously by contacting Crimestoppers on 0800 555 111.